1. Field of the Invention
Allergic asthma, hay fever, and other anaphylactic conditions are treated by a variety of chemotherapeutic agents, of which the following are representative: certain xanthine compounds, particularly aminophylline; some sympathomimetic amines, such as epinephrine; selected cortico-steroids; and disodium cromoglycate.
The disclosed 1-(2-substituted-chromon-yloxy)-2-hydroxy-3-(substituted-phenoxy)propanes demonstrate therapeutic utility in the treatment of such allergic conditions.
2. Description of the Prior Art
Khellin, 4,9-dimethoxy-7-methyl-5H-furo[3,2-g] [1] benzo-pyran-5 one (Formula V), ##SPC5##
was first isolated, and its structure determined, by Spath and Gruber (Ber. 71: 106 [1938]). Khellin subsequently was utilized as a coronary vasodilator, as a bronchodilator, and as an agent for the treatment of colic.
Structural modifications of Khellin led to the synthesis of 5-alkoxy substituted chromone-2-carboxylic acids (Formula VI), ##SPC6##
wherein X can be a variety of substituted alkyl sidechains. Compounds of Formula VI are disclosed by Ellis and Wragg and by Fitzmaurice et al. in British Patent No. 1,049,289 (1966) and No. 1,093,673 (1967) respectively. Such chromone derivatives exhibit biological activity in the treatment of allergic conditions, but such activity is of short duration (see Cox et al., Adv. Drug Res., 5: 118 [1970]). Because of the latter property, the 5-alkoxy substituted chromone-2-carboxylic acids had limited usefulness.
Clinically useful substituted bis-(2-carboxy-chromon-yloxy) derivatives were described by Fitzmaurice et al. in British Patent No. 1,144,905 (1969), particularly disodium chromoglycate, or 1,3-di(2-carboxy-4-oxochromon-5-yloxy)-2-hydroxy-propane disodium salt (Formula VII) ##SPC7##
Disodium chromoglycate, known commercially as Intal, is used to treat allergic bronchial asthma. It produces, however, several untoward side effects.